The objectives of this study are threefold: 1. To define the accuracy of urine cytology in the detection of bladder cancer with special emphasis on the relationship of cytologic findings to tumor characteristics such as histologic type, grade, size and stage and to compare cystoscopy as a diagnostic tool. 2. To refine technical factors in preparation of cytologic material. 3. To study the cytologic, pathologic and biologic evolution of early bladder cancer detected in a preclinical stage by cytology. The study utilizes a large outpatient population, predominantly urologic, in which routine cytology and cystoscopy examinations are performed and complete data on findings are recorded for computer retrieval and analysis. This cytologic screening has yielded 115 patients, without previous history of bladder tumor in whom positive cytologic findings for carcinoma have existed without cytoscopic evidence of neoplasm. Seventy-four of these patients have been subsequently proven to have in situ carcinoma of the bladder and the bladders of 34 of these submitted to total cystectomy have been totally mapped and studied pathologically by step sectioning. The remaining patients are being treated by a variety of modalities and are being closely followed. BIBLIOGRAPHIC REFERENCES: Farrow, G.M., Utz, D.C. and Rife, C.C.: Morphologic and Clinical Observations of Patients with Early Bladder Cancer Treated with Total Cystectomy. Cancer Research. 36:2495-2501 (July) 1976.